This invention relates to a headlamp for motor vehicles of a type including a reflector pivotally adjustable about at least one axis by means of an adjusting device which comprises mainly a threaded nut fastened to the reflector and a threaded shaft, or bolt, rotatably mounted in a fixed (or stationary) part of the headlamp but not being substantially displaceable in an axial direction, and also comprising a scale-like indicating mechanism for indicating the position of the pivotable reflector comprising a stationary part and a moveable part.
Such a headlamp is disclosed in German Auslegeschrift 1 006 738. In order to mount a reflector of this prior art headlamp in an intended position for installation of the headlamp in a motor vehicle, marking lines (or indicia) are provided on edges of a longitudinal slit in a fixed portion of the headlamp. This scale-like indicating apparatus is not suitable however to make a quick inspection as to whether the reflector of a headlamp installed in a motor vehicle is in a proper position. In this regard, it is necessary to have an adjusting mechanism which after the reflector has been adjusted can be reset to a particular value, for example, to an adjusting value of "zero" (0), so that an inspector can remember a particular value, possibly different for each headlamp, in which the reflector takes up a proper position. Such indicating mechanisms are known, for example, from German Gebrauchmuster 89 10 911. Here a bubble level is used which shows whether a reflector has a proper angular slant, or displacement, from vertical. With this adjusting, or indicating, mechanism, it can be inspected if exiting light has a proper inclination to planes of driving lanes.
In German Gebrauchmuster 70 16 497 an indicating mechanism is disclosed having two bubble levels. One of the levels functions as described above, that is, it indicates the reflector position in the vertical direction, while the second level displays the reflector adjustment in the horizontal direction, and no doubt a pivoting of the reflector about an optical axis of the reflector. Because motor vehicle headlamps normally have no adjusting mechanisms with which reflectors can be adjusted about their own optical axes, this inspection possibility is less helpful.
It is therefore an object of this invention to provide an indicating mechanism with which an uncomplicated visual inspection can determine if a reflector is properly adjusted with regard to horizontal pivoting, that is, to make possible an inspection as to whether the optical axis of the reflector runs parallel to a vertical middle plane of a motor vehicle on which the reflector is mounted. In addition, this indicating mechanism should be so formed that it can be simply and quickly placed at a new value, for example at zero value, after each adjustment of the reflector.